If it was me I would be pissed enough to take it to a lonely spot, pour a couple of gallons of gas in & on it, toss a match and walk away. But I'm too bullheaded for the easy way out so I'd get three pieces of paper and put a heading on each one. #1 Cooling System, #2 Ignition/Timing, #3 Fuel Delivery. On each sheet I'd list EVERY component/aspect of that system that could effect the temperature. I would put a check mark by each component that has been changed since the very beginning and a X by every component that has not been changed. I would lay them in front of me and ask,"WHAT THE $%#@? Study them, compare and make notes. Have all of my information & experience right in front of me in one spot. Form new questions note other peoples ideas scratch out what did not work.
At this point I don't think it is in the cooling system. Though there is a ton of interchangeable parts in this engine series not all similar parts are the same. I am thinking about timing gear covers & timing marks on crank pulleys/dampeners. Could there be a miss match here? Just a question. I would turn the engine to TDC according to the timing mark and check the best I could by watching the rockers. If not sure I'd pull the head and make sure the timing mark is right. A little bore camera might help here. If not I'd make a correct mark on the pulley. I'm an old guy, I'd find a points distributer and make sure the points were opening at the right time. I would time it the old fashioned way with the advance disconnected and turning the distributer back & forth till you find the sweet spot. No lights, no gauges, no electronics. Maybe not perfect but close enough to run well & not over heat.
On the fuel side once I was sure the timing was OK I'd start reading the spark plugs. I'd find a lonely stretch of highway where I could make some runs and pull over and pull a plug and check its color. I might set it slightly rich to remove any doubt of over heating due to being lean.All of this can be cleaned up and set or be put back once the problem is found.
If none of this helped I'd find the guy I got the car from a kick his ass.
Last edited by Beater of the Pack; 07/29/23 04:58 PM.
